Doppler Reflectometry Simulations in the Presence of Plasma Turbulence

C. Lechte1, G. Conway2, T. Görler2

Abstract

Doppler reflectometry is a microwave plasma diagnostic for density fluctuations and plasma flows. It is used in fusion plasmas for measuring turbulence and poloidal rotation. In order to correctly interpret the fluctuation measurements, it is
necessary to simulate the propagation and scattering processes of the
wave in the plasma. The fullwave code IPF-FD3D [1] is used to determine the scattering
efficiency, which links the returned signal to the density fluctuation
strength. It depends non-linearly on the plasma density profile and the
magnetic background field. In general, the plasma geometry and density
profile must be known, and some knowledge about the radial structure of
the turbulence is necessary to reconstruct the spectrum from the
reflectometry measurements. The results will be applied to real-world
plasma geometries such as ASDEX Upgrade.